Electric clock.



-EL H. MESSIMRQ H Ei CLC'.. APPLICMLQH man oms. 1914.

Patented Feb, l2; 1918.

l @SHEETS-Sgen 2.

E. H. MESSiTER.

ELECTRIC CLOCK.

APPLlcATloN FILED ums. 19m

Patented Feb. 12, 1918.

4 SHEETS-SHEET 3.

E. H. MESSITER.

ELECTRIC cLocK.

APPLKCATiON FILED DEC.5. |914.l

Patented F6512, 191s@ INVENTOR and a resident of Brooklyn,

- fication,

UNITED :STATES PATENT oEEioE.

EDWIN H. MESSITER, BROOKLYN, NEW YBK.

ELECTRIC cnocx` To all whom z't may' concern:

Be it known` that I, EDWIN H. MEssrrER, a citizen of the United Statesof America, Kings county, and` State of New'Yorlnhave invented certain'new and useful Improvements in Electric Clocks, of which the followingis a specipanying drawings, forming a part thereof.

y invention relates to clocks and other chronological instruments andhas v,special reference 4to such as are maintained in operation byelectricity.

. I am aware that clocks of-theso-called f self-winding type havehitherto been known and in general use. They are provided with electricmotors yfor keeping the main-spring under tension or for raising theweight, the spring or weight being relied upon for directly impartingdriving' forces to the clock mechanism. AW'hile my invention pertains tochronological devices which are driven by electricity, the device of myinvention is of an. entirely different type from those of the prior artto which reference has just been;

made, since I employ and rely directly upon an electric motor foractuating the escapement mechanism.

One object of my invention is-to. provide a simple and `accuratemechanism that shall .avoid the use-of weights, springs and complicatedgearing, and operate with very small friction losses and wear.

' Another` object is to provide a clock` of the character aboveindicated having a direct driving motor which shall act in the dual ca-gpacity of motor and damping device to drive and at the same t1me preventtoo rapid movement of the escapement mechanism.

Another object is to provide a motor that` shall consume a very smallamount of energy, shall operate with great inherent regularity, andwitha substantially constant or uniform torque; in fact a motor that shallbeparticularly adapted to actuate a clock mechanism.

Other objects'and advantages of my in-' vention will be set forthhereinafter,`and in order that my invention may be thoroughlyunderstood, I will now proceed to describe the same in the followingspecification and then vpoint out the novel features thereof in appendedclaims.

I Specification of Letters'l'atent.

reference heilig had to the accomv- Patented Feb.1 2,1918.

AppIication filed December 5, 1914. Serial No.,875,5 76.

Referring to the drawings: Figure 1 isa partially sectional elevation ofa clock mechanism constructed in accordance with and embodying thedriving motor of my invention. -v v' v, A sectional elevation of thesame mechai nism, taken on the line 2'2"of Fig. 1,-isy

shown in Fig. 2.

' Fig. 3 is a sectional view taken on the line 3&3 ,of Fig.` 1 andillustratingthe coperation'b'etween the escapement mechanismand thelever which'it actuates.- k

4 vThe same leverfand the coperating escapenent mechanism isshown inanother pobeingv broken away to show'the construction in detail. I tFig. 8 is a view corresponding to Fig. f1, of

a po'rtion of a modified mechanism in which an impulse is imparted tothe pendulum once instead ofV twice in each complete cycle.

' Fig. 9 corresponds to'I Fig."- 4 and illustrates the escapement andtheactuating lever which are adapted for usewith the structure of Fig. 8.

Fig. 10 is a detail'view of a contact maker which is a part of the samemechanism.

Figs. 11, 12 and ,13 are `diagrammatic f views which show the diii'erentpositions of the armature disk relative to the poles of the' fieldmagnet of the motor and vwhich clearly show the form of the pole faces.

A diagrammatic. view of the circuit/'connections for' the mechanism ofFigs. 1, 2, 3 and 4 is shown in Fig. 14 while a similar view of theconnections for the mechanism of Figs. 8, 9 and 10 is shown in Fig. 15.

Figs. land 17 are respectively a sectional elevation and a detailed viewof a modified motor structure which also embodies my invention.

While I have shown a Denison esca lement 'mechanism which I now considerpreferable,

myinvention is not restricted tothe use of any particular escapement andother well known forms may be employed. The escapement per se forms nopartof my present invention.

As hereinafter more fully pointed out, the structure shown in Figs. 8, 9and 10 is'better adapted for use in chronometers and like 1nvstrumentswhich must operate with great prises an escapement wheel 1G mounted Vona shaft 17, a driving motor 18 operatively connected to the same shaft,a pendulum 19, Vand a pendulum actuating lever or fork 20.

The shaft 1T is supported in bearing sleeves Q1 and 22,which are mountedin stationary plates Q3 and 2a and are insulated therefrom by bushings'25 and 26.

The motor comprises an armature 31, and a field magnet Q7 which, asshown, is provided with a winding 28 and has a pair of opposed polepieces 29-30. The armature 31 comprises a hub 32, a magnetizable disk 33secured thereto and extending between the pole pieces Ql'and 30. anon-magnetizable rim 31 which is U-shaped in cross-section and providesa circumferential channel in which a portion of the armature winding 35is supported.` The air gap existing between the pole faces is notuniform` each of the pole faces being eut back as clearly shown in Figs.11, 12 and 13 to increase the air gap over a portion of thepole faces atone side. The purpose of this arrangement will hereinafter be fullypointedA out in connection with the operation of the device.

Mounted on the shaft 17 in addition to the escapement. 16 and the motorarmature is a lantern p inion 36 which meshes witha train 36 of suitablegearing for propeiling the several hands (not shown) of the clock.

Attention is directed to the fact that power is applied to theescapement shaft v1T which operates at a relatively high speed und '1sgeared down to the slower moving hands of the clock instead of beingapplie'd to the slow moving shafts which are geared up to the eseapementshaft and to the faster moving hands according to usual practice. B vthis means a large amount of friction in the works is avoided and theclock is improved by increasing its accuracy and reliability.

While other well known forms of escapements may be used. I prefer thethree-legged dead-beat escapeinent shown in the drawings. Thisescapement is provided with a plurality'of triangular projections ordriving teeth 37-38-39 which are secured to but are insulated from thebody of the wheel; and radial arms or stopping teeth 410-41--42 The fork20 is pivotally mounted at its upper end by means of a pivot pin 43 andhas an enlargement 4a at its lower end which is apertured to formshoulders 4:3 46 A driving pallet 47 is secured to\and is insulatedfromthe shoulder 45 while a driving pallet 48 is secured to and is inelectrical contact with the shoulder 46. The location of the fork 2O,with reference to the escapement wheel 16 is such that the drivingteeth 3'1"*-38-39 extend into the aperture 49 of the fork and areadapted to engage the driving pallets 46 and 47 as hereinafterexplained. the escapem'ent shaft 17 extending freely through theaperture of the fork.

The fork 2O is also provided with stopping pallets 50-51 which arelaterally opposite each other and are adapted to c0- operate with thestopping teeth of the escapement wheel as hereinafter explained.l

As clearly shown in Fig. 7 the magnetizable armature disk 33 is providedwith notches so that the armature has the form of a wheel with threearms 54, 55 and 56 and the channel-shaped non-magnetizablc rim 34. Thedisk armature is wound with three coils 57 '5S-59, each of which extendsdiametrically across the disk and adjacent to opposite edges of two ofthe arms which have the form of sectors. Each coil comprises a pluralityof turns but has the general form of a semi-circlesince the wires onlyextend across one of the side faces ofthe disk7 the remainder of thecoil beino disposed 'in the channel-shaped rim of the armature. Byreference to Fig. 1 it is therefore evident that onlv that portionA ofthe coil which is adjacent to the flat surface of the disk is influencedby the magnetic lines of force constituting the field existin betweenthe pole pieces 29-30 of the tiel( magnet.

As clearly shown in the diagrammatic view coils vS-,Q isconnected to thearmature disk itself. The other terminal of each is insulated from thedisk and from the shaft but. is connectech to one of the driving teethof the. escapement wheel which, as already pointed out, are insulatedfrom the escapement disk and are electrically independent of each other.The arrangement of parts is obviously such that when one of the drivingteeth 37-38-39 engages the pallet 18. a circuit will be established withone of the coils of the armature.

Before describing the other modifications of my invention l will setforth the operation of the one already described. Assumof Fig. 14.-, oneterminal of each of thel ing that the yparts i ceci-lpg; the positionsshown in Fig. 3, thatthe riving tooth. 39 has just finished 'ving animpulseto the pallet47, driving t efork'20 the penduev lum' 19 to theright, andfnthatthe motion of the escapement'vwheel has been stoppedbythe tooth 40 engaging the pallet 51: the pendulum will now 'completeits swing to the right and its direction of` motion Will befree to turn.y l

When the escapement Wheel is inthe position shown in ig.

' pieces of the magnetas shown in Figs.. 2

' tooth ll2 engagesthe stop pallet 50'the relai tive positionsofthelield magnet and arma- 'and Il.y The magnet winding 28"is lenergizedbut there is no current ina-ny ofthe' armature coils. Under theseconditions the magnetic field existing between the pole faces attractsthe adjacentA sectorsv of the` armature disk tending to draw them into..

the air gap. Inasmuch as theair gap'is greater at the right where thepole faces are cut backthanat the left, the ma etic field is morepowerful at the left an con# sequently the disk amature is moved .to theright, or, in other Words, in a clockwise direction (countersclockwisedirection as viewed in Fig. 2). This movement of v'the disk armatureproduces, of coui.se, a cory responding rotation of theescaper'nentwhee-l.

(in a clockwise direction as viewedin Fig. 3),

and the driving tooth 38'engages pallet 48,-

thereby giving the lever and the penduluman impulse to the left. Thisimpulse is produced bythe magneticaction of the mag? net upon thearmature the armature coils. i

Therotationof the disk armature and of the escapement will continueuntil the independently of ture of the motor being as shown in Fig.12.-v The disk tends to move still fartherr in the same direction byreasonof the same inagl netic action but is prevented at this time fromdoing so by the pallet50. The pendulum now' continues its swing to theleft and on its return stroke the escapement wheel is'again released.lVhen released it turns a little farther in a clockwise direction bythe'magnetic impulse as" above indicated and the driving tooth 39engages Ipallet 48. The field and armature are now Immediately, whencontact is made, one of the coils of the arinature is energized and byreason of thecur I y i shown in Figs. 8, 9 'and '1 0 to which refer# asshown in Fig. 13.

rent transversing the coil a new impulse is imparted to the disk inthe'same direction 3, the, armature. disk- 33 is in the positionrelative to the-'pole' :of eachk coil is influenced'l b r.ing thevcoils, thedireetion of in whichftliey are shown in Fig. 3, except .thatanother driving tooth has taken the position occupied by the tooth 39.The cycle is repeated aslong as current is supplied ."It isevident thatVif thearmature coil were notenergized there would be no 4tendency forthe armature to move in th'e same direction after the rst impulse, butthe-coil is pdesigned andfwound so that when it is energized vtheinfluence of 'the magetic ifield upon itis vstronger than the influenceof the field upon the adjacent magnetizable arm...

of the armature and `is exerted so as to iinypart ,another-impulse inthe same direction, 4vto the armature.

The 'circuit--jconnections may be traced able source of ener-gy` tofield magnet winding28 through a conductor' 91,'circuit being` completedthrough conductor 92 tothe op; posite terminal of the'battery. ofthedriving teeth of the escapement,l as

)for example ,the tooth 38 engages the drivjing`pallet48a motor circuitis temporarily .I completedfrom the conductor 91,.'through a branch 93,bearing sleeve 22, shaft 17, arma- .ture disk 33, armature coil 59,conductor 94,

tooth 38,,pallet 48, fork 20 and pivot pin 43 whichis connected to theframe23 and to conductor 92. The coils are-so wound andformed that only;a single radialsection y the field of force at vone time .and by`suitably connectmotion is alwaysclockwise.

lthe resulting ioo l By slightly modifying the actiiatin'g'lever l 20 asshown in Figi 6, byadding theretoga light resilient contact ,member '60,they-apl paratus may be made self-starting- 'The re-i silient contact issubstantiallyUshaped` and is attached to the lever within the aperture 49 and extends just into the y of the driving teeth 37-38-f39 and insuchposition that whenever the clock is stopped path of .travel Aand thependulum and leverjcome'to rest in` a centralposition one ofthedrivingteeth' will enga-getlie spring and thereby bein 'position to completea'circuit through one of the` armature coilsas :soon as 'energy issupplied to the vreceiving circuit of thefclock, This feature isparticularly valuable for'.

large clocks'orsuch asini'e located kwith their worksv in' a relativelyinaccessible position or with their-.axis secured-.to a rigid base sothat the pendulum cannot readily be started 4vby hand ,0I-'by tiltingthewhole clock..

Another modification-of niyinvention vis ence may now be had. y

Forv particularly laccurate time keeping, it is desirable to insure thata uniform im- CIK its

pulse be imparted to the balan ce Wheel 'or pendulum so that lessreliance 1s placed'on e" e isochronism of these parts. By makingmplitude o1 every oscillationl is the e and consequently theoscillations will made in more nearly equal periods of inne.

In the embodiment of my invention dis- .ised in 1 to 7 inclusive, theimpulses imparted to the pendulum were alternately dependent uponmagnetic attraction, and an electro-dynamic expulsion. The impulsesexerted by the electro-magnetic attract-ions are inherently moreaccurately uniform and regular thanare the impulses which are dependent,not only on the strength ot' the magnetic field but also upon the formand location of the armature coils and the our rent traversing one ofthe coils at any given instant. I have accordingly in the modificat ionof my invention which I will describe in detail hereinafter. utilizedonly the electrtrruagnetic attractive impulses flor transmitting themotion to the pendulum and 'have utilized the electro-dynamic impulsesmerely for the purpose of moving the disk armature into a position forthe next magnetic impulse to be effected. lVith this arrangement it istherefore obvious that the pendulum will always receive an impulse inthe same direction instead of being propellcd alternately in oppositedirections: in other words, the pendulum receives an impulse once ineach complete cycle instead of twice in each complete cycle of itsmovement. In order to avoid, to an even greater y extent thepossibilities of error, a permanent magnet may be utilized instead ofthe electro-magnet shown in the drawings for producing the motor eld.

This arrangement secures the advantages of the gravity or remontoireescapement, generally used in astronomical clocks as well :is thosepertaining to the semi-independent escapement commonly used in marineand other chronometers.

Corresponding parts are designated by the same reference characters asthose employed in theprevious ligures. The bearing sleeves 2l and 22 arenot in this case insulated from the stationary supporting plates 23 and24C and the coils of the disk armature instead of being connected to thedriving teeth 37-38-39 of the escapement are respectively connected to aplurality of projecting pins 61-62-63 which are insulated from andextend laterally from a disk 64 and are successively engaged by arelatively stationary yielding contact finger 65 (see Figs. 10 and 15).The disk 64 is secured to the shaft 17 adjacent to the disk armature orat some other convenient point, and in fact the pins can be mounted onthe armaimpulse equal to every other impulse ture itself if desired. Thepins correspond in number and location to the driving teeth of theescapement. The pendulum actuating lever 20a, as shown in Fig. 9, hasonly a. single driving pallet 47 `which is not insulated from the leverand receives a driving impulse once for each complete cycle of theescapement wheel instead of a driving.

movement. The free movement is such as to bring the next sector of thedisk armature into position to be attracted by the field magnet.

Still another modification of my invention is shown in Figs. 16 and 17of the drawings.

Referring to these figures the structure here shown comprises a diskarmature which is similar to the disk 33 of the motor already described.It has no armature winding and consequently the non-magnetizable rim issuperfluous. Instead of a single field magnet, it is provided with apermanent magnet 70 having pole pieces 71 and 72, and an elec tromagnet73 which is located on the opposite side of the disk axis and has polepieces 74 and 75. Each pair of pole pieces corresponds in form to thepole pieces 29 and 30 of the motor 18.

The Winding 7 6 of the electro-magnet, instead of being constantlyenergized is controlled by a circuit closer and is periodicallyenergized.

The circuit closer may be comprised of the escapement wheel drivingteeth, coperating with one of the driving pallets of the pendulum lever,or a separate circuit closer, as for example the circuit closer 7S, maybe provided. This device is similar to the circuit closer 6e of theprevious figures and need not be described again in detail.

The operation of this motor is as follows: Assuming that theelectro-magnet is deenergizcd, the permanent magnet produces a 60 degreeadvancement of the escapelnent wheel. This stroke draws one of the ironsegments of the disk armature into the air gap of the permanent magnet.In this posi tion, the circuit closer completes a circuit through thecoil of the electro-magnet and thereby another forward movement of thearmature is produced, the electro-magnet being arranged to exertsuiiicient force to overpowcr the permanent magnet. The action of theescapement `wheel in imparting impulses to the pendulum is the same ashereinbetore described.

The permanent magnet may be replaced by a second electro-magnet whichmay then beA energized in alternation with the first, but I prefer to`use the permanent magnet and utilize its impulses for driving thependulum or balance wheel of the clockv for the sake of uniformity ofaction.

The electro-magnets may be made to operate with a high degree ofaccuracy by designing the magnetic circuit to operate over the knee ofthe saturation curve where variations in the magnetizing currents have avery small effect upon the magnetic field.

The lower end of the fork 20*t may be entirely cut away in the formshown in Fig. 9 ifdesired, as only a single driving pallet is use j Itis evident that various structural modifications may be effected withinthe spirit and scope of my invention and I intend that only suchlimitations be imposed as are indicated in the appended claims,

What I claim is: i

1. An electrically propelled clock cornprising an isochronous vibrator,an escapement, a driving shaft-therefor, and an electric driving motorconnected to directly act upon said shaft. i

2. A clock comprising an escapement, a driving shaft therefor and amotor havin an armature directly attached to said sha arranged to imparta succession of rotative l ing an escapement and a rotary motor impulsesto the shaft. f.

3. A clock comprising a pendulum, an escapement, a driving shafttherefor and an electric motor arranged to imparta succession ofrotative impulses to the shaft, and means for controlling theperiodicity of thel motor impulses.

4. A clock comprising a pendulum, an escapement,`a driving shafttherefor and an electric motor arranged to im art a succession ofrotative impulses to t eshaft, and means dependent upon the escapementfor controlling the periodicity of the motor impulses.

5. A clock comprising av'pendulum, ai, resi capement, a driving shafttherefor, and an electric motor adapted to impart a suc ession ofrotative impulses te the shaft and comprising a field magnet, a diskarmature, armature coils therefor, and means dependent upon theescapement for controlling energization of the coils.

(3. A clock comprising a pendulum, a pendulum fork, an escapement havinga plural- I' ity of electrically independent driving teeth, a drivingshaft for the escapement, anelectric motor mounted on the shaft, andcoils for the motor adapted to be successively energized in'response tothe coperative action of the escapement and the pendulum fork.

7. A clock comprising a pendulum, a pendulum fork having drivingpallets, a source of electric energy connected to one of the drivingpallets, an escapement comprising a plurality of electricallyindependent driving teeth, a driving shaft for the escapement, anelectric motor mounted on the shaft and having a plurality of armaturecoils respectively connected to the driving teeth of the escapement, theopposite terminals of said coils being connected to the source ofelectric energy.

8. A clock comprising a pendulum, a pendulum forkhaving driving pallets,a source of electric energy connected to one of the driving pallets, anescapement comprising a plurality of electrically independent drivingteeth, a driving shaft4 for the escapement, an electric motor comprisinga field magnet adapted toproduce Ia constant magnetic field, a diskarmature mounted on the shaft an'd arranged to cut the magnetic field, aplurality of coils extending diametrically across one face ofthe diskarmature, a nonma-gnetizable circumferential support in which `theremainders of the coils-are mounted, said coils being electricallyconnected at one end to the said source of energy and at their oppositeends to the respective driving teeth of the escapement, whereby thecoils are successively energized as the driving teeth make contact withthe electrically active driving pallet.

9.An electrically propelled clock comprisadapted to operate atsubstantially,- the speed of the escapement and connected to drive saidescapement.

driving shaft therefor and an electric motor arranged to impartsuccession of rotative impulses to the shaft, and means dependent uponthe escapement for controlling the periodicity of the motor impulses.

11. A clock comprising an escapement, va driving shaft therefor, and anelectric motor adapted to impart a succession of rotative imp ulses tothe shaft and comprising a field magnet, a disk armature, armature coilstherefor, and means dependent upon the escapement forcontrollingenergization f of the coils.

l. ico 10. A clock comprising an escapement, a

Sion of uni-directional impulses are impart-- ed to the shaft, and meansdependent upon the escapement for controlling the periodicity of themotor impulses.

14. A clock comprising an escapement, a

driving shaft therefor, an electric motor comprising means tending toexert e succession of rotative lmpulses to the shaft alternating indirection, and electro-responsive means controlled by the ,escapementfor counteracting alternate impulses whereby a succession ofunidirectional impulses are imparted to the shaft.

In Witness whereof I have hereunto set iny hand in the presence of twosubscribing 15

